+
+* ispage()
+
+ Tests whether the attachment will be treated by ikiwiki as a wiki page.
+ (Ie, if it has an extension of ".mdwn", or of any other enabled page
+ format).
+
+ So, if you don't want to allow wiki pages to be uploaded as attachments,
+ use `!ispage()` ; if you only want to allow wiki pages to be uploaded
+ as attachments, use `ispage()`.
+
+* user(username)
+
+ Tests whether the attachment is being uploaded by a user with the
+ specified username. If openid is enabled, an openid can also be put here.
+
+* ip(address)
+
+ Tests whether the attacment is being uploaded from the specified IP
+ address.